This invention is directed to water shut off systems, particularly to a water shutoff valve incorporated in the water supply line of a household for automatically shutting off the flow of water into the household in the event of a leak or break in the water supply line.
Oftentimes, it is desired that the water supply to a house or other type of dwelling be shut off. This is particularly true when the householders are leaving their house for a prolonged period, as for example, when going on vacation. However, shutting off the main water supply valve is a chore which is often overlooked in the last minute preparations prior to leaving the house. The purpose of shutting off the water supply is to prevent damage to the house should an extensive leak occur while the householder is away. Rarely is the water supply into a house shut off when the householder is away for a short period of time, as for example, when at work. Yet, cumulative leakage from a burst pipe can cause tremendous damage to the house and contents even if discovered and stopped within a relatively short period of time.
Another problem encountered by householders, particularly in the summer months, is a leaking water faucet or one that has not been completely turned off. Thousands of gallons of water may be wasted from a partially open water faucet left unattended.
Water shutoff systems are known in the prior art as exemplified by U.S. Pat. No. 4,180,088 to Mallett. The Mallett patent discloses a water shutoff system incorporating a flow sensing valve which detects flow in a water line and electrically powers a line valve to the closed position. An on/off control switch in the electrical sensing circuit permits the system to be conveniently turned off and on. The water shutoff system of Mallett is responsive to flow in the line and is connected to a selecting switch so that the switch can be turned to a position wherein water can be used, and also switched to a safety position wherein flow of water causes interruption of the water system valve. A disadvantage with the Mallett apparatus is that the device does not continually monitor water flow through the valve, thus requiring the householder to set the valve to the safety position for detection of water leakage.